(1) Technical Field
This invention relates to bellows or concertina-type covers as used for protecting reciprocating and otherwise movable parts of machinery.
(2) Description of the Prior Art
The prior art covers are best illustrated in U.S. Pat. No. 3,642,309 wherein a bellows-like cover is made in at least two sections, each of which are formed from annular bellows-like assemblies and wherein annular end elements on the bellos-like sections take the form of apertured discs having radial slots which extend inwardly from the outer periphery of one of the elements and outwardly from the inner periphery of the other element to permit the coupling together of the sections. The arrangement is such that the sections of the cover can be readily connected together and readily disconnected by bringing the radially positioned oppositely disposed slots in the joining elements into registry with one another. Accidental registry of the slots will permit the ready disassembly of the sections of the cover and the undersirable exposure of the mechanical parts normally protected thereby.
A bellows-like cover permitting concertina-like movement as well as twisting movement may be seen in U.S. Pat. No. 4,125,130 wherein the bellows is made up of a plurality of co-axially joined bellows elements, each having a plurality of parallelogram shaped wall elements of thin material to permit twisting of the assembled bellows. The degree of twisting provided is limited and unusual flexing of the material of the bellows results in relatively short life and the exposure of mechanical devices on which the bellows is used for protecting the same.
A unitary bellos-type joint assembly for connecting tubular members is disclosed in U.S. Pat. No. 3,873,137, the joint assembly of the disclosure includes short tubular joint sections and a longer bellows section interposed therebetween and detachably connected to the short joint sections. An interlocking water-tight connection is thus formed and no provision is made for rotating a portion of the joint assembly with respect to another portion.
This invention provides all of the advantages of an extremely flexible bellows-like cover formed of a number of annular elements having central openings and joined to one another at their respective peripheral edges and having a unique and extremely simple inter-engaging arrangement of annular elements with center openings slidably engaged one within the other to provide a dust-tight closure which is both flexible longitudinally as in a conventional bellows and rotatable as desirable in covering an elbow-like joint in a mechanical device in which one part of the mechanical device moves at an angle with respect to the other and rotates relative thereto while in angular disposition.